Proof-of-concept for a segmented composite diving suit offering depth-independent thermal protection.

Heat loss is a major health hazard for divers. It can lead to hypothermia, organ damage, unconsciousness, and eventually death. Hence, thermal protection is essential for diver safety. Typically, protection is provided by wetsuits made of bubbled neoprene. However, neoprene shrinks with depth and loses thermal insulation capability, while thick neoprene suits make swimming exhausting. Herein, a proof-of-concept is presented for a solution to both problems: a 'K-suit' made of thermally-resistive composite segments attached to a thin neoprene suit. The segments are made of hollow glass microspheres embedded in carrier polymer thermally cured in 3D-printed molds based on 3D-scans of the diver's body. The K-suit was compared in field trials with a 7 mm commercial neoprene suit by diving in pairs, while automated dataloggers registered pressure and temperature inside and outside both suits. The K-suit demonstrated +4ºC higher temperature difference than the 7 mm neoprene. Also, divers reported that the K-suit had the ergonomics of a 3 mm neoprene suit. These preliminary results represent a proof-of-concept for the K-suit and promise further improvements with potential impact on diver safety.